Đáp án + Giải thích các bước giải:
`a) 7/6 - 1/6(x - 2) = 1 1/3` $\\$ `=> 7/6-1/6(x-2)=4/3` $\\$ `=> 1/6(x - 2) = 7/6 - 4/3` $\\$ `=> 1/6(x - 2) = 7/6 - 8/6` $\\$ `=> 1/6(x - 2) = -1/6` $\\$ `=> x - 2 = (-1/6) : 1/6 = (-1/6)*6=-1` $\\$ `=> x = -1 + 2 = 1`
Vậy `x = 1`
`b) 20%x +0,4x= 4,5` $\\$ `=> 0,2x + 0,4x = 4,5` $\\$ `=> 0,6x = 4,5` $\\$ `=> x = 4,5:0,6=7,5`
Vậy `x = 7,5`
vì `20% = 20/100=1/5=0,2` và `4,5 : 0,6 = 45/10:6/10=45/10*10/6=45/6=15/2=7,5`
`c) (2|x-1|)* 2 2/3= 5 1/3` $\\$ `=>(2|x-1|)=5 1/3:2 2/3` $\\$ `=> 2|x - 1| = 16/3 : 8/3` $\\$ `=> 2|x - 1| = 16/3*3/8=2` $\\$ `=> |x - 1| = 1 ` $\\$ `=> `\(\left[ \begin{array}{l}x-1=1\\x-1=-1\end{array} \right.\) $\\$ `=>` \(\left[ \begin{array}{l}x=2\\x=0\end{array} \right.\)
Vậy `x in {2;0}`
